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🔗 Mathematics

Wang tiles (or Wang dominoes), first proposed by mathematician, logician, and philosopher Hao Wang in 1961, are a class of formal systems. They are modelled visually by square tiles with a color on each side. A set of such tiles is selected, and copies of the tiles are arranged side by side with matching colors, without rotating or reflecting them.

The basic question about a set of Wang tiles is whether it can tile the plane or not, i.e., whether an entire infinite plane can be filled this way. The next question is whether this can be done in a periodic pattern.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry

The MIM-104 Patriot is a surface-to-air missile (SAM) system, the primary of its kind used by the United States Army and several allied nations. It is manufactured by the U.S. defense contractor Raytheon and derives its name from the radar component of the weapon system. The AN/MPQ-53 at the heart of the system is known as the "Phased Array Tracking Radar to Intercept on Target" which is a backronym for PATRIOT. The Patriot System replaced the Nike Hercules system as the U.S. Army's primary High to Medium Air Defense (HIMAD) system, and replaced the MIM-23 Hawk system as the U.S. Army's medium tactical air defense system. In addition to these roles, Patriot has been given the function of the U.S. Army's anti-ballistic missile (ABM) system, which is now Patriot's primary mission. The system is expected to stay fielded until at least 2040.

Patriot uses an advanced aerial interceptor missile and high-performance radar systems. Patriot was developed at Redstone Arsenal in Huntsville, Alabama, which had previously developed the Safeguard ABM system and its component Spartan and hypersonic speed Sprint missiles. The symbol for Patriot is a drawing of a Revolutionary War-era Minuteman.

Patriot systems have been sold to the Netherlands, Poland, Germany, Egypt, Japan, Israel, Saudi Arabia, Kuwait, Republic of China (Taiwan), Greece, Spain, United Arab Emirates, Qatar and Romania. South Korea purchased several second-hand Patriot systems from Germany after North Korea test-launched ballistic missiles to the Sea of Japan and proceeded with underground nuclear testing in 2006. Jordan also purchased several second-hand Patriot systems from Germany. Poland hosts training rotations of a battery of U.S. Patriot launchers. This started in the town of Morąg in May 2010 but was later moved further from the Russian border to Toruń and Ustka due to Russian objections. On December 4, 2012, NATO authorized the deployment of Patriot missile launchers in Turkey to protect the country from missiles fired in the civil war in neighboring Syria. Patriot was one of the first tactical systems in the U.S. Department of Defense's (DoD) to employ lethal autonomy in combat.

The Patriot system gained notoriety during the Persian Gulf War of 1991 with the claimed engagement of over 40 Iraqi Scud missiles, but those claims became a source of controversy. The system was successfully used against Iraqi missiles in 2003 Iraq War, and has been also used by Saudi and Emirati forces in the Yemen conflict against Houthi missile attacks. The Patriot system achieved its first undisputed shootdowns of enemy aircraft in the service of the Israeli Air Defense Command. Israeli MIM-104D batteries shot down two Hamas UAVs during Operation Protective Edge on August 31, 2014 and later, on September 23, 2014, an Israeli Patriot battery shot down a Syrian Air Force Sukhoi Su-24 which had penetrated Israeli airspace, achieving the first shootdown of a manned enemy aircraft in the world for the system.

🔗 United States 🔗 Law 🔗 Indigenous peoples of North America

The Indian Citizenship Act of 1924, (43 Stat. 253, enacted June 2, 1924) was an Act of the United States Congress that granted US citizenship to the indigenous peoples of the United States. While the Fourteenth Amendment to the United States Constitution defines a citizen as any persons born in the United States and subject to its laws and jurisdiction, the amendment had previously been interpreted by the courts not to apply to Native peoples.

The act was proposed by Representative Homer P. Snyder (R-NY), and signed into law by President Calvin Coolidge on June 2, 1924. It was enacted partially in recognition of the thousands of Native Americans who served in the armed forces during the First World War.

🔗 Color

YInMn Blue (for yttrium, indium, manganese), also known as Oregon Blue, Mas Blue, or Yin Min Blue, is an inorganic blue pigment that was discovered accidentally by Professor Mas Subramanian and his then-graduate student Andrew E. Smith at Oregon State University in 2009. It is the first inorganic blue pigment discovered in 200 years, since cobalt blue was identified in 1802.

The compound has a unique trigonal bipyramidal structure, and further research has discovered it may be modified to create green, purple, and orange pigments.

🔗 Telecommunications

A payphone (alternative spelling: pay phone) is typically a coin-operated public telephone, often located in a telephone booth or in high-traffic outdoor areas, with pre-payment by inserting money (usually coins) or by billing a credit or debit card, or a telephone card. Prepaid calling cards also facilitate establishing a call by first calling the provided toll-free telephone number, entering the card account number and PIN, then the desired telephone number. An equipment usage fee may be charged as additional units, minutes or tariff fee to the collect/third-party, debit, credit, telephone or prepaid calling card when used at payphones. By agreement with the landlord, either the phone company pays rent for the location and keeps the revenue, or the landlord pays rent for the phone and shares the revenue.

Payphones are often found in public places to contribute to the notion of universal access to basic communication services. One thesis, written as early as 2003, recognised this as a digital divide problem.

In the 20th century, payphones in some countries, such as Spain, used token coins, available for sale at a local retailer, to activate pay phones, instead of legal tender coins. In some cases, these were upgraded to use magnetic cards or credit card readers over the years.

In the past, payphones were ubiquitous worldwide, but their prevalence has decreased significantly over the years due to the increasing availability of mobile phones, even though cell phone service is not always available in emergencies.

🔗 International relations 🔗 Mass surveillance 🔗 Internet 🔗 History 🔗 Computing 🔗 Internet culture 🔗 Economics 🔗 Law 🔗 Business 🔗 Politics 🔗 International relations/International law 🔗 Sociology 🔗 Futures studies 🔗 Capitalism 🔗 Globalization 🔗 Google

Surveillance capitalism has a number of meanings around the commodification of personal information. Since 2014, social psychologist Shoshana Zuboff has used and popularized the term.

🔗 Chemicals

Aluminium oxynitride (marketed under the name ALON by Surmet Corporation) is a transparent ceramic composed of aluminium, oxygen and nitrogen. ALON is optically transparent (≥ 80%) in the near-ultraviolet, visible, and midwave-infrared regions of the electromagnetic spectrum. It is four times as hard as fused silica glass, 85% as hard as sapphire, and nearly 115% as hard as magnesium aluminate spinel. Since it has a cubic spinel structure, it can be fabricated to transparent windows, plates, domes, rods, tubes, and other forms using conventional ceramic powder processing techniques.

ALON is the hardest polycrystalline transparent ceramic available commercially. Because of its relatively low weight, distinctive optical and mechanical properties, and resistance to oxidation or radiation, it shows promise for applications such as bulletproof, blast-resistant, and optoelectronic windows. ALON-based armor has been shown to stop multiple armor-piercing projectiles of up to .50 BMG.

ALON is commercially available in sizes as large as 18-by-35-inch (460 mm × 890 mm; 46 cm × 89 cm) monolithic windows.

🔗 Telecommunications 🔗 Brands

The IBM Simon Personal Communicator (simply known as IBM Simon) is a handheld, touchscreen PDA designed by International Business Machines (IBM), and manufactured by Mitsubishi Electric. BellSouth Cellular Corp. distributed the Simon Personal Communicator in the United States between August 1994 and February 1995, selling 50,000 units. The Simon Personal Communicator was the first personal digital assistant or PDA to include telephony features. The battery lasted only an hour, and flip phones became increasingly slim which led to its demise.

🔗 Biography 🔗 Australia 🔗 Crime 🔗 Death 🔗 Australia/Australian crime 🔗 Australia/Adelaide

The Somerton Man was an unidentified man whose body was found on 1 December 1948 on the beach at Somerton Park, a suburb of Adelaide, South Australia. The case is also known after the Persian phrase tamám shud (Persian: تمام شد), meaning "is over" or "is finished", which was printed on a scrap of paper found months later in the fob pocket of the man's trousers. The scrap had been torn from the final page of a copy of Rubaiyat of Omar Khayyám, authored by 12th-century poet Omar Khayyám.

Following a public appeal by police, the book from which the page had been torn was located. On the inside back cover, detectives read through indentations left from previous handwriting: a local telephone number, another unidentified number, and text that resembled a coded message. The text has not been deciphered or interpreted in a way that satisfies authorities on the case.

Since the early stages of the police investigation, the case has been considered "one of Australia's most profound mysteries". There has been intense speculation ever since regarding the identity of the victim, the cause of his death, and the events leading up to it. Public interest in the case remains significant for several reasons: the death occurred at a time of heightened international tensions following the beginning of the Cold War; the apparent involvement of a secret code; the possible use of an undetectable poison; and the inability of authorities to identify the dead man.

On 26 July 2022, Adelaide University professor Derek Abbott, in association with genealogist Colleen M. Fitzpatrick, claimed to have identified the man as Carl "Charles" Webb, an electrical engineer and instrument maker born in 1905, based on genetic genealogy from DNA of the man's hair. South Australia Police and Forensic Science South Australia have not verified the result, but South Australia Police said they were "cautiously optimistic" about it.

🔗 United States 🔗 International relations 🔗 Soviet Union 🔗 Russia 🔗 Politics 🔗 Media 🔗 Journalism

Whataboutism, also known as whataboutery, is a variant of the tu quoque logical fallacy that attempts to discredit an opponent's position by charging them with hypocrisy without directly refuting or disproving their argument. It is particularly associated with Soviet and Russian propaganda. When criticisms were leveled at the Soviet Union during the Cold War, the Soviet response would often be "What about..." followed by an event in the Western world. As Garry Kasparov noted, it is a word that was coined to describe the frequent use of a rhetorical diversion by Soviet apologists and dictators, who would counter charges of their oppression, "massacres, gulags, and forced deportations" by invoking American slavery, racism, lynchings, etc. It has been adopted by other politicians and countries.